Loss of national citizenship is possible only under the following circumstances:
The revolutionary changes in the 18th century changed citizenship into being more inclusive and democratic, with a focus on national citizenship.
Until they acquired one or other of the national citizenships, these people continued to be British subjects without citizenship.
If national citizenship does not foster these new rights, then global citizenship may seem more accessible.
If true, this places a strain in the relationship between national and global citizenship.
They do not in any way take the place of national citizenship.
My more general remark is really about European citizenship and national citizenship.
A large number of them intermarried, took up the national citizenship after independence - because they had faced no alternatives.
It will be difficult enough comfortably to relate national and Community citizenships.